android - 如何在android中解析复杂的JSON文件

Question

我需要解析这个json字符串

 {
"results": {
    "result": [
        {
            "cover": "http://ia.media-imdb.com/images/M/MV5BMjMyOTM4MDMxNV5BMl5BanBnXkFtZTcwNjIyNzExOA@@._V1._SX54_CR0,0,54,74_.jpg",
            "title": "The Amazing Spider-Man",
            "year": "(2012",
            "director": "Marc Webb",
            "rating": "7.3",
            "details": "http://www.imdb.com/title/tt0948470/"
        },
        {
            "cover": "http://i.media-imdb.com/images/SF1f0a42ee1aa08d477a576fbbf7562eed/realm/feature.gif",
            "title": "The Amazing Spider-Man 2",
            "year": "(2014",
            "director": "N/A",
            "rating": "N/A",
            "details": "http://www.imdb.com/title/tt1872181/"
        },
        {
            "cover": "http://ia.media-imdb.com/images/M/MV5BMzk3MTE5MDU5NV5BMl5BanBnXkFtZTYwMjY3NTY3._V1._SX54_CR0,0,54,74_.jpg",
            "title": "Spider-Man",
            "year": "(2002",
            "director": "Sam Raimi",
            "rating": "7.3",
            "details": "http://www.imdb.com/title/tt0145487/"
        },
        {
            "cover": "http://ia.media-imdb.com/images/M/MV5BODUwMDc5Mzc5M15BMl5BanBnXkFtZTcwNDgzOTY0MQ@@._V1._SX54_CR0,0,54,74_.jpg",
            "title": "Spider-Man 3",
            "year": "(2007",
            "director": "Sam Raimi",
            "rating": "6.3",
            "details": "http://www.imdb.com/title/tt0413300/"
        },
        {
            "cover": "http://ia.media-imdb.com/images/M/MV5BMjE1ODcyODYxMl5BMl5BanBnXkFtZTcwNjA1NDE3MQ@@._V1._SX54_CR0,0,54,74_.jpg",
            "title": "Spider-Man 2",
            "year": "(2004",
            "director": "Sam Raimi",
            "rating": "7.5",
            "details": "http://www.imdb.com/title/tt0316654/"
        }
    ]
}
}

我获得了所有数据...但是我无法显示从“封面”标签中获得的图像网址...从现在开始最简单的方法是什么...？ http://ia.media-imdb.com/images/M/MV5BMjMyOTM4MDMxNV5BMl5BanBnXkFtZTcwNjIyNzExOA@@._V1._SX54_CR0,0,54,74_.jpg

---

我已经从 http json 数据在 ListView 中实现了 Android 延迟加载图像和文本，现在我想让列表项可点击，但我无法弄清楚在这种情况下如何做到这一点

    public class MainActivity extends Activity {

ListView mListView;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);    

    final TextView txts=(TextView) findViewById(R.id.textView1);
    String URL1=getIntent().getExtras().getString("URL");


    // URL to the JSON data 
    String strUrl = URL1;

    // Creating a new non-ui thread task to download json data 
    DownloadTask downloadTask = new DownloadTask();

    // Starting the download process
    downloadTask.execute(strUrl);

    // Getting a reference to ListView of activity_main
    mListView = (ListView) findViewById(R.id.lv_countries);


   }

    /** A method to download json data from url */
    private String downloadUrl(String strUrl) throws IOException{
    String data = "";
    InputStream iStream = null;
    try{
            URL url = new URL(strUrl);

            // Creating an http connection to communicate with url 
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

            // Connecting to url 
            urlConnection.connect();

            // Reading data from url 
            iStream = urlConnection.getInputStream();

            BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

            StringBuffer sb  = new StringBuffer();

            String line = "";
            while( ( line = br.readLine())  != null){
                sb.append(line);
            }

            data = sb.toString();

            br.close();

    }catch(Exception e){
            Log.d("Exception while downloading url", e.toString());
    }finally{
            iStream.close();
    }

    return data;
      }



      /** AsyncTask to download json data */
     private class DownloadTask extends AsyncTask<String, Integer, String>{
    String data = null;
            @Override
            protected String doInBackground(String... url) {
                    try{
                        data = downloadUrl(url[0]);

                    }catch(Exception e){
                        Log.d("Background Task",e.toString());
                    }
                    return data;
            }

            @Override
            protected void onPostExecute(String result) {

                    // The parsing of the xml data is done in a non-ui thread 
                    ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();

                    // Start parsing xml data
                    listViewLoaderTask.execute(result);

            }
      }

    /** AsyncTask to parse json data and load ListView */
     private class ListViewLoaderTask extends AsyncTask<String, Void, SimpleAdapter>{

    JSONObject jObject;
    // Doing the parsing of xml data in a non-ui thread 
    @Override
    protected SimpleAdapter doInBackground(String... strJson) {
        try{
            jObject = new JSONObject(strJson[0]);
            CountryJSONParser countryJsonParser = new CountryJSONParser();
            countryJsonParser.parse(jObject);
        }catch(Exception e){
            Log.d("JSON Exception1",e.toString());
        }

        // Instantiating json parser class
        CountryJSONParser countryJsonParser = new CountryJSONParser();

        // A list object to store the parsed countries list
        List<HashMap<String, Object>> countries = null;

        try{
            // Getting the parsed data as a List construct
            countries = countryJsonParser.parse(jObject);
        }catch(Exception e){
            Log.d("Exception",e.toString());
        }          

        // Keys used in Hashmap 
        String[] from = { "country","flag","details"};

        // Ids of views in listview_layout
        int[] to = { R.id.tv_country,R.id.iv_flag,R.id.tv_country_details};

        // Instantiating an adapter to store each items
        // R.layout.listview_layout defines the layout of each item         
        SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), countries,        
        return adapter;
    }

    /** Invoked by the Android on "doInBackground" is executed */
    @Override
    protected void onPostExecute(SimpleAdapter adapter) {

        // Setting adapter for the listview
        mListView.setAdapter(adapter);

        for(int i=0;i<adapter.getCount();i++){
            HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(i);
            String imgUrl = (String) hm.get("flag_path");
            ImageLoaderTask imageLoaderTask = new ImageLoaderTask();

            HashMap<String, Object> hmDownload = new HashMap<String, Object>();
            hm.put("flag_path",imgUrl);
            hm.put("position", i);

            // Starting ImageLoaderTask to download and populate image in the listview 
            imageLoaderTask.execute(hm);
        }
    }       
}

   /** AsyncTask to download and load an image in ListView */
  private class ImageLoaderTask extends AsyncTask<HashMap<String, Object>, Void, HashMap<St

    @Override
    protected HashMap<String, Object> doInBackground(HashMap<String, Object>... hm) {

        InputStream iStream=null;
        String imgUrl = (String) hm[0].get("flag_path");
        int position = (Integer) hm[0].get("position");

        URL url;
        try {
            url = new URL(imgUrl);

            // Creating an http connection to communicate with url
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

            // Connecting to url                
            urlConnection.connect();

            // Reading data from url 
            iStream = urlConnection.getInputStream();

            // Getting Caching directory 
            File cacheDirectory = getBaseContext().getCacheDir();

            // Temporary file to store the downloaded image 
            File tmpFile = new File(cacheDirectory.getPath() + "/wpta_"+position+".png");               

            // The FileOutputStream to the temporary file
            FileOutputStream fOutStream = new FileOutputStream(tmpFile);

            // Creating a bitmap from the downloaded inputstream
            Bitmap b = BitmapFactory.decodeStream(iStream);             

            // Writing the bitmap to the temporary file as png file
            b.compress(Bitmap.CompressFormat.PNG,100, fOutStream);              

            // Flush the FileOutputStream
            fOutStream.flush();

            //Close the FileOutputStream
            fOutStream.close();             

            // Create a hashmap object to store image path and its position in the listview
            HashMap<String, Object> hmBitmap = new HashMap<String, Object>();

            // Storing the path to the temporary image file
            hmBitmap.put("flag",tmpFile.getPath());

            // Storing the position of the image in the listview
            hmBitmap.put("position",position);              

            // Returning the HashMap object containing the image path and position
            return hmBitmap;                


        }catch (Exception e) {              
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(HashMap<String, Object> result) {
        // Getting the path to the downloaded image
        String path = (String) result.get("flag");          

        // Getting the position of the downloaded image
        int position = (Integer) result.get("position");

        // Getting adapter of the listview
        SimpleAdapter adapter = (SimpleAdapter ) mListView.getAdapter();

        // Getting the hashmap object at the specified position of the listview
        HashMap<String, Object> hm = (HashMap<String, Object>)   adapter.getItem(position); 

        // Overwriting the existing path in the adapter 
        hm.put("flag",path);

        // Noticing listview about the dataset changes
        adapter.notifyDataSetChanged(); 
    }
}

    @Override
   public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
  }
  }

如何做到？

Answer 1

首先请看一些教程，例如:

http://www.androidhive.info/2012/01/android-json-parsing-tutorial/

http://www.vogella.com/articles/AndroidJSON/article.html

JSONObject response = new JSONObject(respString);
ArrayList<Book> bookCollection = new ArrayList<Book>();//
    if(response.has("results")){
        if(response.has("result")){
            JSONArray resultArray = response.getJSONArray("result");
            for(int iCount=0; iCount<resultArray.length; iCount++){
                JSONObject item = resultArray.getJSONObject(iCount);
                Book book = new Book();
                if(item.has("title")){
                    book.title =item.getString("title");
                }
                bookCollection.add(book);
            }
        }
    }

---

要填充的 pojo

public Book{

public String cover;
public String title;

}